Few can match Alistair Brownlee, the favourite for Tuesday's men's triathlon, when it comes to the demands of the 1500m swim, 40km bike ride and 10km run. But earlier this year a "little man from the council" nearly achieved what the world's fittest athletes have struggled to do – knock the Briton's gold medal hopes off course.

After tearing a tendon in January, Brownlee installed a swimming pool with an underwater treadmill in his garden in Horsforth, Yorkshire, to help him continue training. Given the pool was facing the main road, he soon became something of a local curiosity. But one neighbour was unhappy with the size of the pool and contacted the council to complain.

Brownlee, who is the reigning world champion, said: "When I tore my Achilles I thought 'this is the Olympics coming up I'm going to have to do something special to get myself in shape as quickly as I can.' I was doing aqua jogging in a public pool in public sessions with kids jumping on my head and old grannies telling me I shouldn't be there. I was thinking: 'This is ridiculous, I'm going to the Olympics in six months!' So I decided to get a pool of my own and put it in the garden."

It took Brownlee's triathlon friends and team-mates a week to dig a hole big enough to fit the pool and, having spent three weeks with his foot in a cast, Brownlee was keen to build up his fitness.

"The neighbours all claimed to be all right with it but someone put a complaint in and one day some little man from the council came round and asked if I had planning permission," said Brownlee. "Apparently the pool has to be under 50% of the size of your garden and he was arguing it was over that."

Luckily at that point, Malcolm Brown, the Olympic Performance Manager for British Triathlon, arrived and managed to persuade the official not to take things further. "I came into the house just as the man from the council was just leaving shaking his head," he said. "We managed to persuade him the measurements he had taken were just slightly out. Consequently it didn't require planning permission."

Brownlee added: "The pool is 16ft in length. It's got a jet in it so you can swim or run against the current. I spent three weeks in a cast and another week when I couldn't ride a bike. So it was a month without cycling. The pool made a huge difference."

Brownlee's recovery from injury has been slow, but in his one full-length triathlon this season, in Kitzbühel, he beat all his major rivals, including his brother Jonny to victory. He goes into Tuesday's race in Hyde Park as a strong favourite having won 12 of the 15 world series races he has entered since 2009. However he faces stiff competition from his brother, who has finished in the top three in his last 13 races at elite level – winning six of them.

"He was a bit of a nightmare when he was injured," said Jonny Brownlee. "When I saw him in March, I never thought he'd get to the position he is now. Back then he was depressed. He'd put a bit of weight on. He was different. But once he started training I knew he'd get back quickly."